In order to create various light effects and mood lighting in connection with concerts, live shows, TV shows, sport events or as a part of an architectural installation light fixtures creating various effects are getting more and more used in the entertainment industry. Typically, entertainment light fixtures create a light beam having a beam width and a divergence and can for instance be wash/flood fixtures creating a relatively wide light beam with a uniform light distribution or it can be profile fixtures adapted to project image onto a target surface.
Typically, such light fixtures comprise a least one light source generating a light beam propagating along an optical axis and an optical assembly configured to project the light beam along the optical axis. Light fixtures for entertainment can comprise a number of light effect components which are configured to be inserted into the light beam in order to provide different light effects. The light effect components can for instance be any light effects known in the art of intelligent/entertainments lighting, for instance a CMY color mixing system, color filters, gobos, animation effects wheels, iris diaphragms, focus lenses, zoom lenses, prism effect components, framing systems or any other light effects known in the art. Moving head light fixture comprising a base, a yoke and a head are often used in connection with entertainment lighting as they, in addition to the light effects described above, can also direct the light into various directions.
Light designers and programmers want as many effects as possible in a light fixture as this gives the light designer and programmers many options when creating light shows. Additionally light designers and programmers constantly also have a desire to have a silent light fixture were the noise generated by the light fixture is as low as possible.
U.S. Pat. No. 3,545,301 discloses a vibration damper for mounting on the output shaft of an electrical stepping motor wherein a viscoelastic absorber element is fixedly interposed between the motor output shaft and a damping mass, with the polar mass moment of inertia of the latter being a function of the polar mass moment of inertia of the motor armature. The polar mass momentum of inertia of damping mass is taken to be in the range of 10 to 60% (preferably 50%) of that of the motor.